It is clear that Cloud computing is and will be a sea change for the Information Technology by changing the way in which both software and hardware are designed and purchased. In this work we address the use of this emerging computing paradigm into web hosting providers in order to avoid its resource management limitations. Thanks to the Cloud approach, resources can be provided in a dynamic way according with the needs of providers and end-users. In this paper, we present an elastic web hosting provider, namely Cloud Hosting Provider (CHP), that makes use of the outsourcing technique in order to take advantage of Cloud computing infrastructures for providing scalability and high availability capabilities to the web applications deployed on it. Furthermore, we pursue the main goal of maximizing the revenue earned by the provider through both the analysis of Service Level Agreements (SLA) and the employment of an economic model. The evaluation exposed demonstrates that the system proposed is able to properly react to the dynamic load received by the web applications and it also achieve the aforesaid revenue maximization of the provider by performing an SLA-aware resource (i.e. web servers) management.